Variants of the coronavirus SARS-CoV-2
RIVM monitors changes in the coronavirus SARS-CoV-2 in the Netherlands and the consequences of those changes. When a virus replicates, it can change very slightly every time. These changes (or mutations) are usually so small that they have almost no effect on the properties of the virus, such as how ill you become and how the virus spreads. Sometimes changes do cause a virus to behave differently, for example allowing it to spread more easily.